WO2023239273A1

WO2023239273A1 - A method of pre-coding a data packet for a multi-antenna transmitter and receiver arrangement, a computer program product, a non-transitory computer-readable storage medium, a multi-antenna transmitter and receiver arrangement, a wireless device, and a transceiver node

Info

Publication number: WO2023239273A1
Application number: PCT/SE2023/050483
Authority: WO
Inventors: Joakim Axmon; Bengt Lindoff
Original assignee: Beammwave Ab
Priority date: 2022-06-10
Filing date: 2023-05-17
Publication date: 2023-12-14

Abstract

A method (100) for a multi-antenna transmitter and receiver arrangement (400), the multi-antenna transmitter and receiver arrangement (400) being comprisable in a wireless device, WD or in a transceiver node, TNode, the method comprising: obtaining (110) a data packet type for a data packet to be transmitted to a remote TNode; pre-coding (120) the data packet to be transmitted based on the obtained data packet type. Corresponding computer program product, multi-antenna transmitter and receiver arrangement, wireless device, and transceiver node are also disclosed.

Description

A method of pre-coding a data packet for a multi-antenna transmitter and receiver arrangement, a computer program product, a non-transitory computer-readable storage medium, a multi-antenna transmitter and receiver arrangement, a wireless device, and a transceiver node

Technical field

The present disclosure relates to a method of pre-coding a data packet for a multiantenna transmitter and receiver arrangement, a computer program product, a non-transitory computer-readable storage medium, a multi-antenna transmitter and receiver arrangement, a wireless device, and a transceiver node.

More specifically, the disclosure relates to a method of pre-coding a data packet for a multi-antenna transmitter and receiver arrangement, a computer program product, a non- transitory computer-readable storage medium, a multi-antenna transmitter and receiver arrangement, a wireless device, and a transceiver node as defined in the introductory parts of the independent claims.

Background art

In multiple-input multiple-output (MIMO) and beamforming systems, i.e., where a communication between transmission nodes using multiple transmit and receive antennas is performed, one often utilizes reciprocity of the channel in the communication, meaning that the beamforming weights used for reception is reused when transmitting. Reciprocity is especially utilized if the beamforming architecture is based on analog or hybrid beamforming, i.e., where beamforming is performed using analog phase shifters. In this case, the beam directions are limited and the time for beam switching is typically long and therefore for reduced complexity the same beamforming weights are used for transmission and reception.

There are some inherent deficiencies using such approach since depending on the radio channel characteristics and type of data transmission, using reciprocity may not achieve optimal performance. Therefore, there may be a need for a method and an apparatus for improved transmission beamforming control.

EP 3304969 Al discloses a method for transmitting data by a transmission node in a wireless communication system. The method includes transmitting, to a base station, a channel information request, transmitting, to the base station, a data packet based on a first channel information value received in response to the transmitted channel information request, and awaiting reception of a response packet indicating reception of the data packet from the base station, if the reception of the response packet fails during a predetermined time interval, detecting an energy level of a signal received in the predetermined time interval, and reconfiguring one of a transmitting method for the response packet and a transmitting method for a next data packet based on the detected energy level.

US 20130294369 Al discloses that a base station receives channel state information from a wireless device. The base station transmits to the wireless device one or more data packets on a data channel employing a first precoding matrix identifier. The base station transmits one or more control packets on a control channel to the wireless device employing a second precoding matrix.

However, there may still be a need to achieve a higher signal-to-noise ratio (SNR), and/or to utilize less power, e.g., when the radio channel(s) comprises multi-path Non-Line-of-Sight (NLOS) signals from different (e.g., non-adjacent) directions.

An object of the present disclosure is to mitigate, alleviate or eliminate one or more of the above-identified deficiencies and disadvantages in the prior art and solve at least the above-mentioned problem.

According to a first aspect there is provided a method for a multi-antenna transmitter and receiver arrangement, the multi-antenna transmitter and receiver arrangement being comprisable in a wireless device, WD or in a transceiver node, TNode, the method comprising: obtaining a data packet type for a data packet to be transmitted to a remote TNode; determining if the data packet to be transmitted is of a first data packet type or a second data packet type, different from the first data packet type; pre-coding the data packet to be transmitted based on the obtained data packet type, wherein pre-coding comprises: performing pre-coding in a first pre-coding mode associated with a first beamwidth if the data packet to be transmitted is determined to be of the first data packet type; and performing precoding in a second pre-coding mode associated with a second beamwidth if the data packet to be transmitted is determined to be of the second data packet type, wherein the second pre- coding mode is different from the first pre-coding mode, and wherein the first beamwidth comprises more spatial directions than the second beamwidth. According to some embodiments, the method further comprises obtaining channel characteristics for a plurality of radio channels between the remote TNode and the multi-antenna transmitter and receiver arrangement.

According to some embodiments, pre-coding is further based on the obtained channel characteristics.

According to some embodiments, the method further comprises deriving a channel tap filter length from the obtained channel characteristics.

According to some embodiments, performing pre-coding in the first pre-coding mode comprises allocating a first transmit power associated with a first number of channel taps; and performing pre-coding in the second pre-coding mode comprises allocating a second transmit power associated with a second number, different from the first number, of channel taps.

According to some embodiments, the first and second numbers of channel taps are less than or equal to the channel tap filter length.

According to some embodiments, the method further comprises deriving a time delay and optionally a coefficient from the obtained channel characteristics.

According to some embodiments, performing pre-coding in the first pre-coding mode comprises utilizing a first set of phase shifts, scaling factors and time delays for the data packet to be transmitted, and performing pre-coding in the second pre-coding mode comprises utilizing a second set of phase shifts, scaling factors and time delays for the data packet to be transmitted.

According to some embodiments, the first and second sets of phase shifts, scaling factors and time delays are determined based on the channel tap filter length and/or the time delay and optionally the coefficient derived from the obtained channel characteristics.

According to some embodiments, the first data packet type is a retransmission of the data packet, and the second data packet type is a first transmission of a data packet. According to some embodiments, a data packet of the first data packet type comprises random access, common data information and/or control data, and a data packet of the second data packet type comprises dedicated data information.

According to some embodiments, the method further comprises transmitting the data packet to be transmitted.

According to some embodiments, the first pre-coding mode has a first beamwidth; the second pre-coding mode has a second beamwidth; and the first beamwidth is different from, such as broader than, the second beamwidth.

According to some embodiments, the pre-coding is performed in one or more of a complex frequency domain, a wavelet domain, a frequency domain, a spatial domain, and a time domain.

According to a second aspect there is provided a computer program product comprising instructions, which, when executed on at least one processor of a processing device, cause the processing device to carry out the method according to the first aspect or any of the embodiments mentioned herein.

According to a third aspect there is provided a non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of a processing device, the one or more programs comprising instructions which, when executed by the processing device, causes the processing device to carry out the method according to the first aspect or any of the embodiments mentioned herein.

According to a fourth aspect there is provided a multi-antenna transmitter and receiver arrangement, comprising control circuitry configured to cause: obtainment of a data packet type for a data packet to be transmitted to a remote TNode; determination of if the data packet to be transmitted is of a first data packet type or a second data packet type, different from the first data packet type; and pre-coding of the data packet based on the obtained data packet type. Pre-coding comprises: performing pre-coding in a first pre-coding mode, associated with a first beamwidth, if the data packet to be transmitted is determined to be of the first data packet type; and performing pre-coding in a second pre-coding mode, associated with a second beamwidth, wherein the second pre-coding mode is different from the first precoding mode, if the data packet to be transmitted is determined to be of the second data packet type, and wherein the first beamwidth comprises more spatial directions than the second beamwidth. According to some embodiments, the control circuitry is further configured to cause transmission of the pre-coded data packet.

According to some embodiments, the multi-antenna transmitter and receiver arrangement comprises a transmitter arrangement comprising: a pre-coder configured to precode data packets in a complex frequency domain, a wavelet domain, or a frequency domain; a first beamforming processing unit configured to convert the pre-coded data packets from a complex frequency domain, a wavelet domain, or a frequency domain to a time domain; a second beamforming processing unit configured to process the pre-coded data packets in one or more of a spatial domain and a time domain to obtain digital signals; a control unit configured to determine coefficients for the first and/or the second beamforming processing unit; combiners configured to combine the digital signals to obtain combined digital signals; and conversion units configured to convert each of the (e.g., a third plurality of) combined digital signals to respective analog signals.

According to some embodiments, the multi-antenna transmitter and receiver arrangement comprises a receiver arrangement. The receiver arrangement comprises analog to digital converters configured to convert analog radio signals into digital radio signals; an extraction unit configured to extract reference signals from each of the digital radio signals; and a channel analyzer configured to determine characteristics for each of the digital radio signals based on the extracted reference signals.

According to some embodiments, the multi-antenna transmitter and receiver arrangement comprises transceivers configured to transmit each of the analog signals via antenna units and optionally configured to receive analog radio signals via the antenna units.

According to some embodiments, the multi-antenna transmitter and receiver arrangement comprises a switch configured to switch the transceivers between the transmitter arrangement and the receiver arrangement.

According to a fifth aspect there is provided a wireless device (WD) comprising the multi-antenna transmitter and receiver arrangement.

According to a sixth aspect there is provided a transceiver node (TNode) comprising the multi-antenna transmitter and receiver arrangement. Effects and features of the second, third, fourth, fifth, and sixth aspects are fully or to a substantial extent analogous to those described above in connection with the first aspect and vice versa. Embodiments mentioned in relation to the first aspect are fully or largely compatible with the second, third, fourth, fifth, and sixth aspects and vice versa.

An advantage of some embodiments is that robustness is increased/improved (e.g., against uncertainty/variations in the radio channel).

Another advantage of some embodiments is a reduced complexity and/or increased flexibility, e.g., by performing beamforming in one or more domains.

Yet another advantage of some embodiments, is that digital and/or hybrid beamforming (pre-coding) is enhanced, e.g., since beamforming (pre-coding) can be gradually adapted in the digital domain.

A further advantage of some embodiments is that the complexity of the beamforming processing is reduced, e.g., if some beamforming is performed in the time domain.

Yet a further advantage of some embodiments is that performance in uplink (UL) communication between (from) a WD/TNode, implemented with a digital BF transceiver architecture and (to) a remote TNode is improved or optimized, e.g., if data packets of a first data packet type are transmitted in one (spatial) direction and data packets of a second data packet type are transmitted in another (spatial) direction especially if the remote TNode is using an analog or hybrid BF transceiver architecture that can only receive/transmit in a single or a few spatial directions.

The present disclosure will become apparent from the detailed description given below. The detailed description and specific examples disclose preferred embodiments of the disclosure by way of illustration only. Those skilled in the art understand from guidance in the detailed description that changes, and modifications may be made within the scope of the disclosure.

Hence, it is to be understood that the herein disclosed disclosure is not limited to the particular component parts of the device described or steps of the methods described since such apparatus and method may vary. It is also to be understood that the terminology used herein is for purpose of describing particular embodiments only and is not intended to be limiting. It should be noted that, as used in the specification and the appended claims, the articles "a", "an", "the", and "said" are intended to mean that there are one or more of the elements unless the context explicitly dictates otherwise. Thus, for example, reference to "a unit" or "the unit" may include several devices, and the like. Furthermore, the words "comprising", "including", "containing" and similar wordings does not exclude other elements or steps. Furthermore, the term "configured" or "adapted" is intended to mean that a unit or similar is shaped, sized, connected, connectable, programmed or otherwise adjusted for a purpose.

Brief of the

The above objects, as well as additional objects, features, and advantages of the present disclosure, will be more fully appreciated by reference to the following illustrative and non-limiting detailed description of example embodiments of the present disclosure, when taken in conjunction with the accompanying drawings.

Figure 1A is a schematic drawing illustrating method steps according to some embodiments;

Figure IB is a schematic drawing illustrating a multi-antenna transmitter and receiver arrangement according to some embodiments;

Figure 2 is a schematic drawing illustrating a computer readable medium according to some embodiments;

Figure 3 is a flowchart illustrating method steps implemented in a multi-antenna transmitter and receiver arrangement, or in a control unit/control circuitry thereof, according to some embodiments;

Figure 4 is a schematic drawing illustrating a conversion unit according to some embodiments;

Figure 5 is a schematic drawing illustrating a switch for switching transceivers between the transmitter arrangement and the receiver arrangement according to some embodiments; and Figure 6 is a schematic drawing illustrating a receiver arrangement connected to transceivers and antennas according to some embodiments.

Detailed description

The present disclosure will now be described with reference to the accompanying drawings, in which preferred example embodiments of the disclosure are shown. The disclosure may, however, be embodied in other forms and should not be construed as limited to the herein disclosed embodiments. The disclosed embodiments are provided to fully convey the scope of the disclosure to the skilled person.

Terminology

Below is referred to a wireless device (WD). A wireless device is any device capable of transmitting or receiving signals wirelessly. Some examples of wireless devices are user equipment (UE), mobile phones, cell phones, smart phones, Internet of Things (loT) devices, vehicle-to-everything (V2X) devices, vehicle-to-infrastructure (V2I) devices, vehicle-to-network (V2N) devices, vehicle-to-vehicle (V2V) devices, vehicle-to-pedestrian (V2P) devices, vehicle- to-device (V2D) devices, vehicle-to-grid (V2G) devices, fixed wireless access (FWA) points, and tablets.

Below is referred to a "transceiver node" (TNode). A TNode may be a remote radio unit (RRU), a repeater, a remote wireless node, or a base station (BS), such as a radio base station (RBS), a Node B, an Evolved Node B (eNB) or a gNodeB (gNB). Furthermore, a TNode may be a BS for a neighboring cell, a BS for a handover (HO) candidate cell, a remote radio unit (RRU), a distributed unit (DU), another WD or a base station (BS) for a (active/deactivated) secondary cell (SCell) or for a serving/primary cell (PCell, e.g., associated with an active TCI state).

Below is referred to millimeter Wave (mmW) operation, mmW communication, mmW communication capability and mmW frequency range. The mmW frequency range is from 24.25 Gigahertz (GHz) to 71 GHz or more generally from 24 to 300 GHz. MmW may also be referred to as Frequency Range 2 (FR2).

Below is referred to a first and second beamforming processing units. The processing unit may be a digital processor. Alternatively, the processor may be a microprocessor, a microcontroller, a central processing unit, a co-processor, a graphics processing unit, a digital signal processor, an image signal processor, a quantum processing unit, or an analog signal processor. The processing unit may comprise one or more processors and optionally other units, such as a control unit.

Below is referred to a digital interface. A digital interface is a unit converting analog signals from e.g., transceivers to digital signals, which digital signals are conveyed to e.g., a baseband processor, and/or converting digital signals from e.g., a baseband processor to analog signals, which analog signals are conveyed to e.g., one or more transceivers. A digital interface possible also comprises filters and other pre-processing functions/units.

Below is referred to an antenna unit. An antenna unit may be one single antenna. However, an antenna unit may also be a dual antenna, such as a dual patch antenna with a first (e.g., horizontal) and a second (e.g., vertical) polarization, thus functioning as two separate antennas or an antenna unit having two ports.

Below is referred to a chip. A chip is an integrated circuit (chip) or a monolithic integrated circuit (chip) and may also be referred to as an IC, or a microchip.

Below is referred to a "filter". A filter is a device or process that removes some features, components, or frequencies from a signal.

Herein is referred to a "spatial direction". A spatial direction is a direction in space. The spatial direction may be a vertical direction and/or a horizontal direction (e.g., 3D MIMO). Herein a spatial direction is defined as a direction in which the beam/signal power has a local maximum, which is separated from other local maxima (i.e., other spatial directions) by at least one local minimum of the beam/signal power. Thus, an adjacent/adjoining spatial direction is a direction in which the beam/signal power has a local maximum, which is separated from the local maximum of the spatial direction it is adjacent/adjoined to by one (and only one) local minimum of the beam/signal power. In some embodiments, each spatial direction is separated from the adjacent spatial direction with the same angle.

Below is referred to a "channel tap". A channel tap is typically associated with a radio path in a particular spatial direction (whereas another channel tap is associated with a radio path in another spatial direction). In some embodiments, the channel tap is represented by a complex number. Herein is referred to "analog beamforming", "hybrid beamforming" and "digital beamforming". Digital beamforming means that the beamforming processing, e.g., multiplication of a coefficient, is performed before digital to analog conversion (DAC) for transmission (and after analog to digital conversion, ADC, for reception), i.e., in the digital domain. Analog beamforming means that the beamforming processing, e.g., phase shifting, is performed after DAC for transmission (and before ADC for reception), i.e., in the analog domain. Hybrid beamforming means that some beamforming processing, e.g., phase shifting, is performed after DAC and some beamforming processing, e.g., multiplication of a coefficient, is performed before DAC for transmission (and before and after ADC for reception), i.e., processing in both digital and analog domains.

Basic concept

A basic concept of the invention is to perform the transmission (TX) pre-coding, e.g., beamforming, of one or more data packet(s) in different ways depending on the type of data packet the data packet(s) belongs to. E.g., if the data packet is of a first type, such as a control data packet, a random access data packet, or a retransmission data packet, pre-coding is performed in a first pre-coding mode (e.g., with a first transmit power, a first beamwidth, in a first spatial direction etc.) and if the data is of a second type, such as a first transmission of a data packet or dedicated data information, pre-coding is performed in a second pre-coding mode (e.g., with a second transmit power, a second beamwidth, in a second spatial direction etc.), different from the first pre-coding mode (i.e., the first transmit power is different from the second transmit power, the first beamwidth is different from the second beamwidth, the first direction different from the second direction etc.). In some embodiments, the first beamwidth is broader than the second beamwidth. By utilizing a narrower beamwidth, i.e., the second beamwidth, for a first transmission of a data packet, a high signal-to-noise ratio (SNR) may be achieved. Furthermore, performance in UL communication between a WD/TNode and a remote TNode is improved or optimized, e.g., if data packets of a first data packet type are transmitted in one (spatial) direction and data packets of a second data packet type are transmitted in another (spatial) direction (preferably implemented with a digital BF transceiver architecture, since analog BF can only listen/receive/transmit in a single spatial direction and hybrid BF only in a few directions/sections).

Embodiments

In the following, embodiments will be described where figure 1A illustrates method steps according to some embodiments and figure IB illustrates a multi-antenna transmitter and receiver arrangement according to some embodiments. The method 100 is for a multiantenna transmitter and receiver arrangement 400. Furthermore, the multi-antenna transmitter and receiver arrangement 400 is comprisable or comprised in a wireless device (WD) or in a transceiver node (TNode), i.e., in some embodiments a WD or a TNode comprises the multi-antenna transmitter and receiver arrangement 400. The method 100 comprises obtaining 110 a data packet type for a data packet to be transmitted (from the multi-antenna transmitter and receiver arrangement 400, the WD or the TNode) to a remote TNode. In some embodiments, the data packet type is one of retransmission of the data packet and a first transmission of a data packet. Furthermore, the method 100 comprises pre-coding 120 the data packet to be transmitted based on the obtained data packet type. Moreover, in some embodiments, the method 100 comprises transmitting 130 (e.g., with an allocated transmission/transmit power), e.g., to a remote TNode, the data packet to be transmitted. In some embodiments, the method 100 comprises obtaining 112 channel characteristics for a plurality of radio channels between the remote TNode and the multi-antenna transmitter and receiver arrangement 400 (or between the remote TNode and a WD/TNode comprising the multi-antenna transmitter and receiver arrangement 400). In some embodiments, the channel characteristics is radio channel characteristics. In these embodiments, the pre-coding 120 is further based on the obtained channel characteristics. Alternatively, the pre-coding 120 is based on received pilot symbols or synchronisation signal blocks (SSBs). As yet another alternative, the pre-coding 120 is based on channel tap filter length. Channel characteristics may be obtained in either frequency domain or time domain or in a combination of frequency and time domain. Channel taps etc. may be derived regardless of whether the characteristics are determined in frequency or time domain by utilizing well-known relationships between frequency (f) and time (t). Furthermore, in some embodiments, the method 100 comprises determining 116 if the data packet to be transmitted is of a first data packet type or a second data packet type. In these embodiments, the method 100 comprises performing 122 precoding in a first pre-coding mode if the data packet to be transmitted is determined to be of a first data packet type; and performing 124 pre-coding in a second pre-coding mode if the data packet to be transmitted is determined to be of a second data packet type, different from the first data packet type. The second pre-coding mode is different from the first pre-coding mode (e.g., with a different allocated transmit power and/or having a different beamwidth, or spatial directions). In some embodiments, the first data packet type is a retransmission of the data packet, and the second data packet type is a first transmission of a data packet. Alternatively, or additionally, a data packet of the first data packet type comprises random access, common data information and/or control data, and a data packet of the second data packet type comprises dedicated data information, e.g., only dedicated data information (and no random access, common data information or control data). The determining 116 is, in some embodiments, based on an instruction or indication received from the remote TNode. Alternatively, determining 116 is performed by determining the type of data present in a transmit buffer (i.e., a buffer comprising the data for transmission). As yet another alternative, the determining 116 is based on a transmission request from a transmission controller of the multi-antenna transmitter and receiver arrangement 400 (or of the WD or TNode comprising the multi-antenna transmitter and receiver arrangement 400).

Moreover, in some embodiments, the method 100 comprises deriving (or obtaining or calculating) 114 a channel tap filter length from the obtained channel characteristics. In these embodiments performing pre-coding 120 in the first pre-coding mode comprises allocating 123 a first transmit power associated with a first number of channel taps, and performing precoding 120 in the second pre-coding mode comprises allocating 125 a second transmit power associated with a second number of channel taps. The second number is different from the first number, thus, in some embodiments the first transmit power is different from the second transmit power. However, in other embodiments, the first and second (total) transmit power is the same (even though the second number is different from the first number). In some embodiments, the transmit power per channel tap is larger in the first pre-coding mode than in the second pre-coding mode (e.g., if the first and second transmit power is the same and the second number of channel taps is larger than the first number of channel taps). Furthermore, in some embodiments, the first and second numbers of channel taps are less than or equal to the channel tap filter length, i.e., the first number of channel taps is less than or equal to the channel tap filter length and the second number of channel taps is less than or equal to the channel tap filter length. E.g., the first number is 1, the second number is 2 and the channel tap filter length is 2. In some embodiments, the first transmit power is higher than the second transmit power.

In some embodiments, the method 100 comprises deriving (or obtaining or calculating)

115 a time delay (e.g., in the form of power delay profile, PDP) from the obtained channel characteristics. The method 100 may also comprise deriving (or obtaining or calculating) a coefficient (e.g., a channel filter tap or a coefficient for a channel filter tap) from the obtained channel characteristics. In these embodiments, performing pre-coding in the first pre-coding mode comprises utilizing 126 a first set of phase shifts, scaling factors and time delays for the data packet to be transmitted, and performing pre-coding 120 in the second pre-coding mode comprises utilizing 128 a second set of phase shifts, scaling factors and time delays for the data packet to be transmitted. Each of the first and second sets may comprise one or more phase shifts, one or more scaling factors and/or one or more time delays. In some embodiments, the first set is different from the second set. The first and second sets of phase shifts, scaling factors and time delays are determined based on the channel tap filter length and/or the time delay and optionally the coefficient derived from the obtained channel characteristics. E.g., the phase shifts of the first and second sets are determined based on the (in step 114 derived) channel tap filter length, the scaling factors of the first and second sets are determined based on the derived coefficient, and the time delays of the first and second sets are determined based on the derived time delay. Adapting pre-coding by changing the time-delay, coefficient and/or phase shift for (channel or filter) taps in uplink (UL) communication compared to the estimated time delay, coefficient and/or phase shift for (channel or filter) taps in downlink (DL) communication increases/improves robustness, e.g., since the risk of destructive combining at the Tnode communication is performed with (i.e., the remote TNode) is reduced, due to radio transceiver impairments (e.g., PLL phase noise) and/or channel variation due to differences between reception and transmission time and/or movement of the Tnode/WD. The scaling factors may be coefficient scaling factors for scaling of coefficients, such as channel/filter coefficients or beamforming weights. Furthermore, in some embodiments, the first and second sets of phase shifts, scaling factors and time delays each comprises one or more of phase shifts, scaling factors and time delays, i.e., in some embodiments, the first and second sets comprises only phase shifts, only time delays or only phase shifts and time delays. In some embodiments, all scaling factors are set to 1, whereby no scaling is performed. Furthermore, in some embodiments, the scaling factors are utilized to allocate transmit power, e.g., first and/or second transmit power. Moreover, in some embodiments, the pre-coding 120 is implemented by filtering the data packet(s) with a filter comprising filter coefficients. The filter coefficients may be obtained/derived/calculated based on the corresponding set of phase shifts, scaling factors and time delays (first set if in the first pre-coding mode or if the data packet is of the first data packet type and second set if in the second pre-coding mode or if the data packet is of the second data packet type).

In some embodiments, the first pre-coding mode gives/has, or is associated with, a first beamwidth, and the second pre-coding mode gives/has, or is associated with, a second beamwidth. E.g., in the first pre-coding mode, the data packet to be transmitted is pre-coded to be transmitted with a first beamwidth and in the second pre-coding mode, the data packet to be transmitted is pre-coded to be transmitted with a second beamwidth. The first beamwidth is different from the second beamwidth. In some embodiments, the first beamwidth comprises more spatial directions than the second beamwidth. Alternatively, or additionally, the first beamwidth is broader than the second beamwidth. E.g., the first beamwidth may include many, several (such as more than 3 spatial directions) or all spatial directions (i.e., be omnidirectional; i.e., the beam is formed widely to comprise many or all spatial directions) and the second beamwidth may be a single spatial direction or a few spatial directions, such as 2 or 3 spatial directions (i.e., the beam is formed narrowly to comprise only one or a few spatial directions). In some embodiments, the second beamwidth comprises one single spatial direction or a few (e.g., 2 or 3) adjacent/adjoining spatial directions, whereas the first beamwidth comprises several (e.g., 4 or more) adjacent/adjoining spatial directions. Alternatively, the second beamwidth comprises a few (e.g., 2 or 3) adjacent/adjoining spatial directions, whereas the first beamwidth comprises several (e.g., 4 or more) non-adjacent/non- adjoining spatial directions. As yet another alternative, the second beamwidth comprises a few (e.g., 2 or 3) adjacent/adjoining spatial directions, whereas the first beamwidth comprises several (e.g., 4 or more) spatial directions, and wherein one or two or more of the spatial directions of the first beamwidth are adjacent/adjoining and the rest (at least one) of the spatial directions of the first beamwidth are non-adjacent/non-adjoining (to each of the one or more adjacent/adjoining spatial directions of the first beamwidth). This may be beneficial, e.g., when the radio channel(s) comprises multi-path Non-Line-of-Sight (NLOS) signals from different directions. Furthermore, the second beamwidth may be obtained by utilizing a lower number of transceivers/antennas for transmission than for the first beamwidth. Alternatively, or additionally, the second beamwidth may be obtained by utilizing less power for one or more transceivers/antennas than for the first beamwidth. In some embodiments, the second pre-coding mode does not utilize reciprocity for transmission and reception, e.g., the second pre-coding mode utilizes beamforming weights, beamwidth, or a set of phase shifts, scaling factors and/or time delays for transmission which is different from the beamforming weights, the beamwidth or the set of phase shifts, scaling factors and/or time delays utilized for reception whereas the first pre-coding mode utilizes reciprocity for transmission and reception, e.g., the first pre-coding mode utilizes the same beamforming weights, beamwidth or set of phase shifts, scaling factors and/or time delays for transmission and reception, . Alternatively, the first pre-coding mode does not utilize reciprocity for transmission and reception, whereas the second pre-coding mode utilizes reciprocity for transmission and reception.

Furthermore, in some embodiments, the pre-coding 120 is performed in one or more of a complex frequency domain, a wavelet domain, a frequency domain, a spatial domain, and a time domain. As an example, the pre-coding 120 is performed in the frequency domain only. As another example, the pre-coding 120 is performed partly in the frequency domain and partly in the time domain (e.g., if the transceivers utilize orthogonal frequency-division multiplexing, OFDM). As yet another example, the pre-coding 120 is performed in the time domain only. As a further example, the pre-coding 120 is performed (only) in a spatial domain and a time domain, i.e., in a spatio-temporal domain. Thus, as it is possible to select in which domain the pre-coding 120 is performed, an increased flexibility for pre-coding is achieved.

In some embodiments, as shown in figure IB, the multi-antenna transmitter and receiver arrangement 400 comprises a transmitter arrangement 404. The transmitter arrangement 404 comprises a pre-coder 1980. The pre-coder 1980 pre-codes or is configured to pre-code data packets in a complex frequency domain, a wavelet domain, or a frequency domain. Furthermore, the transmitter arrangement 404 comprises a first beamforming processing unit 1940. The first beamforming processing unit 1940 converts or is configured to convert the pre-coded data packets from a complex frequency domain, a wavelet domain, or a frequency domain to a time domain. Moreover, the transmitter arrangement 404 comprises a second beamforming processing unit 1810. The second beamforming processing unit 1810 configured to process the pre-coded data packets in one or more of a spatial domain and a time domain to obtain digital signals. In some embodiments, the second beamforming processing unit 1810 comprises a plurality (m) of filters, such as spatio-temporal filters 1800, ..., 1807. The filters, e.g., the spatio-temporal filters 1800, ..., 1807, processes or are configured to process the pre-coded data packets in one or more of a spatial domain and a time domain to obtain digital signals. In some embodiments, the pre-coder 1980 comprises the first beamforming processing unit 1940. Furthermore, in some embodiments, the pre-coder 1980 comprises the second beamforming processing unit 1810. Moreover, in some embodiments, the pre-coder 1980 comprises the first and second beamforming processing units 1940, 1810. Thus, in some embodiments, the first and/or second beamforming processing is part of the pre-coding. The transmitter arrangement 404 comprises a filter control unit 1920. The filter control unit 1920 determines or is configured to determine coefficients, such as filter coefficients of the plurality (m) of spatio-temporal filters 1800, ..., 1807 or beamforming weights, for the first and/or the second beamforming processing units 1940, 1810. Furthermore, the transmitter arrangement 404 comprises a plurality (N) of combiners 1840, ..., 1847. The combiners 1840, ..., 1847 combines or are configured to combine the plurality (N) of digital signals to obtain a plurality (N), e.g., a third plurality, of combined digital signals. Moreover, the transmitter arrangement 404 comprises a plurality (I) of conversion units 620, ..., 635. The conversion units 620, ..., 635 convert or are configured to convert each of the plurality (N) of combined digital signals to respective analog signals. In some embodiments, there is one conversion unit 620, ..., 635 for each transceiver/analog signal. However, in other embodiments, there are two conversion units for each analog signal, e.g., one for an in-phase (I) branch and one for a quadrature phase (Q) branch. Alternatively, there are four conversion units for each analog signal, e.g., if dual polarized antenna units are utilized and each chip comprises 2 transceivers.

In some embodiments, the multi-antenna transmitter and receiver arrangement 400 comprises a receiver arrangement 402 (shown in figure 6 and described below in connection with figure 6).

Furthermore, the multi-antenna transmitter and receiver arrangement 400 comprises a plurality of transceivers 500, 501, ..., 515. The transceivers 500, 501, ..., 515 transmits or are configured to transmit each of the analog signals via a plurality of (respective) antenna units 700, 701, ..., 715 (e.g., during a transmission mode). In some embodiments, the transceivers 500, 501, ..., 515 receives or are configured to receive a plurality of analog radio signals via the plurality of (respective) antenna units 700, 701, ..., 715 (e.g., during a reception mode).

In some embodiments, the multi-antenna transmitter and receiver arrangement 400 comprises a chip 412 (shown in figure IB). The chip 412 comprises the pre-coder 1980, the first beamforming processing unit 1940, the second beamforming processing unit 1810, the filter control unit 1920 and the combiners 1840, 1847. Furthermore, the chip is clocked with a clock (or an oscillator) having a chip frequency/rate.

However, in some embodiments, the multi-antenna transmitter and receiver arrangement (400) comprises a first chip. The first chip comprises the pre-coder 1980, the first beamforming processing unit 1940 and the filter control unit 1920. Furthermore, the multiantenna transmitter and receiver arrangement (400) comprises a second chip. The second chip comprises the second beamforming processing unit 1810, and the combiners 1840, ..., 1847. Moreover, the multi-antenna transmitter and receiver arrangement 400 comprises a digital interface, DI. The DI interfaces or is configured to interface the first and second chips.

According to some embodiments, a computer program product comprising a non- transitory computer readable medium 200, such as a punch card, a compact disc (CD) ROM, a read only memory (ROM), a digital versatile disc (DVD), an embedded drive, a plug-in card, a random access memory (RAM) or a universal serial bus (USB) memory, is provided. Figure 2 illustrates an example computer readable medium in the form of a compact disc (CD) ROM 200. The computer readable medium has stored thereon, a computer program comprising program instructions. The computer program is loadable into a data processor (PROC) 220, which may, for example, be comprised in a computer 210 or a computing device or a control unit. When loaded into the data processor, the computer program may be stored in a memory (MEM) 230 associated with or comprised in the data processor. According to some embodiments, the computer program may, when loaded into and run by the data processor, cause execution of method steps according to, for example, the method illustrated in figure 1A, which is described herein. Furthermore, in some embodiments, there is provided a computer program product comprising instructions, which, when executed on at least one processor of a processing device, cause the processing device to carry out the method illustrated in figure 1A. Moreover, in some embodiments, there is provided a non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of a processing device, the one or more programs comprising instructions which, when executed by the processing device, causes the processing device to carry out the method illustrated in figure 1A.

Figure 3 illustrates method steps implemented in a multi-antenna transmitter and receiver arrangement 400 (or in a control unit or control circuitry comprised therein or associated therewith, e.g., a processing unit for a wireless device configured to control the multiple antenna transceiver system 400) according to some embodiments. The multi-antenna transmitter and receiver arrangement 400 comprises control circuitry. Alternatively, a WD or a TNode comprising the multi-antenna transmitter and receiver arrangement 400 comprises the control circuitry. The control circuitry causes or is configured to cause obtainment 310 of a data packet type for a data packet to be transmitted to a remote TNode. To this end, the control circuitry may be associated with (e.g., operatively connectable, or connected, to) a first obtainment unit (e.g., first obtaining circuitry or a first obtainer). Furthermore, the control circuitry causes or is configured to cause pre-coding 320 of the data packet based on the obtained data packet type. To this end, the control circuitry may be associated with (e.g., operatively connectable, or connected, to) a pre-coding unit (e.g., pre-coding circuitry or the pre-coder 1980). In some embodiments, the control circuitry causes or is configured to cause transmission 330 of the pre-coded data packet. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) transmission units (e.g., transmitting circuitry or transmitters or transceivers 500, 501, ..., 515 and associated antenna units 700, 701, ..., 715). Furthermore, in some embodiments, the control circuitry causes or is configured to cause obtainment 312 of channel characteristics for a plurality of radio channels between the remote TNode and the multi-antenna transmitter and receiver arrangement 400. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a second obtainment unit (e.g., second obtaining circuitry or a filter control unit 1920). Moreover, in some embodiments, the control circuitry causes or is configured to cause derivation (or obtainment or calculation) 314 of a channel tap filter length from the obtained channel characteristics. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a first derivation unit (e.g., first derivating circuitry or the filter control unit 1920). In these embodiments during performance of precoding 320 in the first pre-coding mode the control circuitry causes or is configured to cause allocation 323 of a first transmit power associated with a first number of channel taps, and during performance of pre-coding 320 in the second pre-coding mode the control circuitry causes or is configured to cause allocation 325 of a second transmit power associated with a second number of channel taps. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) first and second allocation units (e.g., first and second allocation circuitry or first and second allocators). In some embodiments, the control circuitry causes or is configured to cause derivation (or obtainment or calculation) 315 of a time delay (and optionally a coefficient) from the obtained channel characteristics. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a second derivation unit (e.g., second derivating circuitry or the filter control unit 1920). In these embodiments during performance of pre-coding 320 in the first pre-coding mode the control circuitry causes or is configured to cause utilization 326 of a first set of phase shifts, scaling factors and time delays for the data packet to be transmitted, and during performance of pre-coding 320 in the second pre-coding mode the control circuitry causes or is configured to cause utilization 328 of a second set of phase shifts, scaling factors and time delays for the data packet to be transmitted. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) first and second utilization units (e.g., first and second utilization circuitry or first and second utilizers or the pre-coder 1980).

In some embodiments, the control circuitry causes or is configured to cause determination 316 of if the data packet to be transmitted is of a first data packet type or a second data packet type. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a determination unit (e.g., determining circuitry or a determiner or a transmission controller). In these embodiments, the control circuitry causes or is configured to cause performance 322 of pre-coding in the first pre-coding mode if the data packet to be transmitted is determined to be of a first data packet type, and the control circuitry causes or is configured to cause performance 324 of pre-coding in the second precoding mode if the data packet to be transmitted is determined to be of a second data packet type, different from the first data packet type. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) one or more pre-coding units (e.g., pre-coding circuitry or the pre-coder 1980). In some embodiments, the control circuitry causes or is configured to cause performance of first beamforming processing. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a first beamforming processing unit 1940 (e.g., first beamforming processing circuitry or a first beamforming processor or the pre-coder 1980). The first beamforming processing unit 1940 may be one or more of an inverse Discrete Fourier Transformer (IDFT), an Inverse Fast Fourier transformer (IFFT), an Inverse Laplace transformer, an Inverse Wavelet transformer and/or an Inverse Z-transformer. Moreover, in some embodiments, the control circuitry causes or is configured to cause performance of second beamforming processing. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a second beamforming processing unit 1810 (e.g., second beamforming processing circuitry, a second beamforming processor, the pre-coder 1980 or filters, such as spatio-temporal filters 1800, ..., 1807). In some embodiments, the control circuitry causes or is configured to cause determination of coefficients (beamforming weights) for the first and/or the second beamforming processing. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a control unit (e.g., the control unit 1920). Furthermore, in some embodiments, the control circuitry causes or is configured to cause combination of digital signals to obtain combined digital signals. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a plurality of combining units (e.g., combining circuitry or combiners, such as the plurality of combiners 1840, ..., 1847). In some embodiments, the combiners are adders or summers. Moreover, in some embodiments, the control circuitry causes or is configured to cause conversion of each of the combined digital signals to respective analog signals. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a plurality of conversion units (e.g., converting circuitry or converters). In some embodiments, the control circuitry causes or is configured to cause transmission of each of the analog signals. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) transmission units (e.g., transmitting circuitry or transmitters or transceivers 500, 501, ..., 515 with associated antenna units 700, 701, ..., 715).

In some embodiments, the control circuitry causes or is configured to cause reception of a plurality of analog radio signals. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a receiver arrangement 402 (e.g., receiving circuitry or a receiver or transceivers 500, 501, ..., 515). In some embodiments, the control circuitry causes or is configured to cause conversion of the plurality of analog radio signals into a plurality of digital signals. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a receiver arrangement 402 (e.g., receiving circuitry or a receiver or ADCs 600, 601, ..., 615 seen in figure 6). In some embodiments, the control circuitry causes or is configured to cause extraction of reference signals from each of the plurality of digital signals. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a receiver arrangement 402 (e.g., receiving circuitry or a receiver or extraction unit 900/sub-extraction units 901, 902, ..., 916 seen in figure 6). In some embodiments, the control circuitry causes or is configured to cause determination of characteristics for each of the plurality of digital signals based on the extracted reference signals. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a receiver arrangement 402 (e.g., receiving circuitry or a receiver or channel analyzer 920 seen in figure 6). In some embodiments, the control circuitry causes or is configured to cause obtainment of the filter coefficients for the spatiotemporal filters 1800, ..., 1807 based on the determined characteristics. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) a filter coefficient determining unit (e.g., filter coefficient determining circuitry, a filter coefficient determiner, or the filter control unit 1920). Le., in some embodiments, the filter control unit 1920 obtains/receives determined characteristics from the channel analyzer 920 and determines the coefficients (e.g., filter coefficients or beamforming weights) for the first and/or second beamforming processing unit(s) 1940, 1810 based on the determined characteristics. In some embodiments, the control circuitry causes or is configured to cause filtering, such as spatio-temporally filtering. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) filtering or spatio-temporally filtering units (e.g., filtering circuitry, filters, spatio-temporally filtering circuitry or spatio- temporally filters 1800, ..., 1807). In some embodiments, the control circuitry causes or is configured to cause conversion of the (e.g., a third plurality) combined digital signals to a plurality (N) of analog baseband signals. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) digital to analog (DA) conversion units (e.g., digital to analog converting circuitry or DA converters 642). In some embodiments, the control circuitry causes or is configured to cause up-conversion of each of the plurality (N) of analog baseband signals to a respective carrier frequency radio signal. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) up-conversion units (e.g., up-converting circuitry or up-converters 640). In some embodiments, the control circuitry causes or is configured to cause transmitting each of the carrier frequency radio signals. To this end, the controlling circuitry may be associated with (e.g., operatively connectable, or connected, to) transmission units (e.g., transmitting circuitry or transmitters or transceivers 500, 501, ..., 515 and associated antenna units 700,

701, ..., 715).

Figure 4 illustrates a conversion unit 620 according to some embodiments. The conversion unit 620 comprises a digital to analog (DA) converter 642 and an up-converter 640. The DA converter 642 converts a digital signal into an analog signal and the up-converter 640 converts an analog signal, such as a baseband signal, to an analog signal with a higher frequency, such as a carrier frequency radio signal. Although only the converter 620 is shown in figure 4, all converters 620, ..., 635 function the same way (i.e., comprises a DA converter 642 and an up-converter 640).

Moreover, in some embodiments, as illustrated in figure 5, the multi-antenna transmitter and receiver arrangement 400 comprises a switch 406 configured to switch the plurality of transceivers 500, 501, ..., 515 (which are connected or connectable to antenna units 700, 701, ..., 715) between the transmitter arrangement 404 and the receiver arrangement 402. As an example, the switch connects the transmitter arrangement 404 to the transceivers 500, 501, ..., 515 when the multi-antenna transmitter and receiver arrangement 400 enters a transmission mode (and/or while the multi-antenna transmitter and receiver arrangement 400 is in the transmission mode) and the switch connects the receiver arrangement 402 to the transceivers 500, 501, ..., 515 when the multi-antenna transmitter and receiver arrangement 400 enters a reception mode (and/or while the multi-antenna transmitter and receiver arrangement 400 is in the reception mode).

Figure 6 illustrates a receiver arrangement 402 connected to transceivers 500, 501, ..., 515 and to antenna units 700, 701, ..., 715. In some embodiments, the multi-antenna transmitter and receiver arrangement 400 comprises the receiver arrangement 402. The receiver arrangement 402 comprises a plurality of analog to digital (AD) converters 600, 601, ..., 615. The AD converters 600, 601, ..., 615 convert or are configured to convert the plurality of analog radio signals into a plurality of digital (baseband) signals. In some embodiments, there is one AD converter for each receiver/transceiver/analog signal. However, in other embodiments, there are two AD converters for each analog signal, e.g., one for an in-phase (I) branch and one for a quadrature phase (Q) branch. Furthermore, the receiver arrangement 402 comprises an extraction unit 900. The extraction unit 900 extracts or is configured to extract reference signals from each of the plurality of digital signals. In some embodiments, the extraction unit 900 comprises a plurality (N) of sub-extraction units 901, 902, ..., 916, i.e., one sub-extraction unit for each digital signal. Moreover, the receiver arrangement 402 comprises a channel analyzer 920. The channel analyzer 920 determines or is configured to determine characteristics for each of the plurality of digital signals based on the extracted reference signals. In some embodiments, the characteristics is a (time domain) radio channel characteristics. In some embodiments, the characteristics comprises channel estimates, such as radio channel estimates, e.g., for each of the digital signals. In some embodiments, the characteristics comprises (radio) channel filter taps indicative of the radio channel characteristics.

Furthermore, the receiver arrangement 402 comprises a plurality of spatio-temporal filters 800, ..., 807. The spatio-temporal filters 800, ..., 807 are configured to process or processes the plurality of digital signals to obtain a plurality of combined signals. In some embodiments, the receiver arrangement 402 comprises a transform unit 940. The transform unit 940 is configured to transform or transforms each of the plurality of combined signals into a frequency domain. In some embodiments, the transform unit 940 is or comprises a plurality of transform sub-units. Each transform sub-unit is configured (connected and otherwise adapted) to process a respective signal of the plurality of combined signals. In some embodiments, the transform unit transforms each of the combined signals in a serial manner. Furthermore, in some embodiments, the multi-antenna receiver arrangement 400 comprises a post-processing unit 960. The post-processing unit 960 is configured to post-process or postprocesses the transformed signals in the frequency domain to obtain a plurality of frequency domain processed signals. Moreover, in some embodiments, the plurality of analog radio signals is coded. Thus, in some embodiments, the multi-antenna receiver arrangement 400 comprises a decoder 980. The decoder 980 is configured to decode or decodes the plurality of frequency domain processed signals (in order to obtain information signals).

The description has been disclosed in terms of a single MIMO layer and pre-coding with respect to channel characteristics for a single layer. However, in some embodiments, multiple MIMO layers are utilized, e.g., pre-coding with respect to channel characteristics may be applied either in a combined pre-coding with the ordinary MIMO multi-layer pre-coding or as a separate pre-coding per MIMO layer. List of examples:

Example 1

A method (100) for a multi-antenna transmitter and receiver arrangement (400), the multi-antenna transmitter and receiver arrangement (400) being comprisable in a wireless device, WD or in a transceiver node, TNode, the method comprising: obtaining (110) a data packet type for a data packet to be transmitted to a remote TNode; and pre-coding (120) the data packet to be transmitted based on the obtained data packet type.

Example 2

The method of example 1, further comprising: obtaining (112) channel characteristics for a plurality of radio channels between the remote TNode and the multi-antenna transmitter and receiver arrangement (400); and wherein pre-coding (120) is further based on the obtained channel characteristics.

Example 3

The method of any of examples 1-2, further comprising: determining (116) if the data packet to be transmitted is of a first data packet type or a second data packet type; performing (122) pre-coding in a first pre-coding mode if the data packet to be transmitted is determined to be of a first data packet type; and performing (124) pre-coding in a second pre-coding mode, different from the first pre-coding mode, if the data packet to be transmitted is determined to be of a second data packet type, different from the first data packet type.

Example 4

The method of example 3, wherein the first data packet type is a retransmission of the data packet, and the second data packet type is a first transmission of a data packet. Example 5

The method of example 3, wherein a data packet of the first data packet type comprises random access, common data information and/or control data, and a data packet of the second data packet type comprises dedicated data information.

Example 6

The method of any of examples 3-5, further comprising: deriving (114) a channel tap filter length from the obtained channel characteristics; and wherein performing pre-coding (120) in the first pre-coding mode comprises allocating (123) a first transmit power associated with a first number of channel taps; wherein performing pre-coding (120) in the second pre-coding mode comprises allocating (125) a second transmit power associated with a second number, different from the first number, of channel taps; and wherein the first and second numbers of channel taps are less than or equal to the channel tap filter length.

Example 7

The method of example 6, further comprising: deriving (115) a time delay and optionally a coefficient from the obtained channel characteristics; wherein performing pre-coding (120) in the first pre-coding mode comprises utilizing (126) a first set of phase shifts, scaling factors and time delays for the data packet to be transmitted, wherein performing pre-coding (120) in the second pre-coding mode comprises utilizing (128) a second set of phase shifts, scaling factors and time delays for the data packet to be transmitted, and wherein the first and second sets of phase shifts, scaling factors and time delays are determined based on the channel tap filter length and/or the time delay and optionally the coefficient derived from the obtained channel characteristics. Example 8

The method of any of examples 3-7, further comprising: transmitting (130) the data packet to be transmitted.

Example 9

The method of any of examples 3-8, wherein the first pre-coding mode has a first beamwidth; and wherein the second pre-coding mode has a second beamwidth; and wherein the first beamwidth is different from, such as broader than, the second beamwidth.

Example 10

The method of any of examples 1-9, wherein the pre-coding (120) is performed in one or more of a complex frequency domain, a wavelet domain, a frequency domain, a spatial domain and a time domain.

Example 11

A computer program product comprising a non-transitory computer readable medium (200), having stored thereon a computer program comprising program instructions, the computer program being loadable into a data processing unit (220) and configured to cause execution of the method of any of examples 1-10 when the computer program is run by the data processing unit.

Example 12

A multi-antenna transmitter and receiver arrangement (400), comprising control circuitry configured to cause: obtainment (310) of a data packet type for a data packet to be transmitted to a remote TNode; and pre-coding (320) of the data packet based on the obtained data packet type. Example 13

The multi-antenna transmitter and receiver arrangement of example 12, wherein the control circuitry is further configured to cause: transmission (330) of the pre-coded data packet.

Example 14

The multi-antenna transmitter and receiver arrangement (400) of any of examples 12- 13, comprising: a transmitter arrangement (404) comprising: a pre-coder (1980) configured to pre-code data packets in a complex frequency domain, a wavelet domain, or a frequency domain; a first beamforming processing unit (1940) configured to convert the pre-coded data packets from a complex frequency domain, a wavelet domain, or a frequency domain to a time domain; a second beamforming processing unit (1810) configured to process the pre-coded data packets in one or more of a spatial domain and a time domain to obtain digital signals; a control unit (1920) configured to determine coefficients for the first and/or the second beamforming processing unit (1940, 1810); combiners (1840, ..., 1847) configured to combine the digital signals to obtain combined digital signals; conversion units (620, ..., 635) configured to convert each of the third plurality (N) of combined digital signals to respective analog signals; optionally a receiver arrangement (402) comprising: analog to digital converters (600, 601, ..., 615) configured to convert analog radio signals into digital radio signals; an extraction unit (900) configured to extract reference signals from each of the digital radio signals; and a channel analyzer (920) configured to determine characteristics for each of the digital radio signals based on the extracted reference signals; transceivers (500, 501, ..., 515) configured to transmit each of the analog signals via antenna units (700, 701, ..., 715) and optionally configured to receive analog radio signals via the antenna units (700, 701, ..., 715); and optionally a switch (406) configured to switch the transceivers (500, 501, ..., 515) between the transmitter arrangement (404) and the receiver arrangement (402).

Example 15

A wireless device, WD, comprising the multi-antenna transmitter and receiver arrangement (400) of any of examples 12-14.

Example 16

A transceiver node, TNode, comprising the multi-antenna transmitter and receiver arrangement (400) of any of examples 12-14.

Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. Reference has been made herein to various embodiments. However, a person skilled in the art would recognize numerous variations to the described embodiments that would still fall within the scope of the claims. For example, the method embodiments described herein discloses example methods through steps being performed in a certain order. However, it is recognized that these sequences of events may take place in another order without departing from the scope of the claims. Furthermore, some method steps may be performed in parallel even though they have been described as being performed in sequence. Thus, the steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. In the same manner, it should be noted that in the description of embodiments, the partition of functional blocks into particular units is by no means intended as limiting. Contrarily, these partitions are merely examples. Functional blocks described herein as one unit may be split into two or more units. Furthermore, functional blocks described herein as being implemented as two or more units may be merged into fewer e.g., a single) unit. Any feature of any of the embodiments/aspects disclosed herein may be applied to any other embodiment/aspect, wherever suitable. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Hence, it should be understood that the details of the described embodiments are merely examples brought forward for illustrative purposes, and that all variations that fall within the scope of the claims are intended to be embraced therein.

Claims

1. A method (100) for a multi-antenna transmitter and receiver arrangement (400), the multi-antenna transmitter and receiver arrangement (400) being comprisable in a wireless device, WD or in a transceiver node, TNode, the method comprising: obtaining (110) a data packet type for a data packet to be transmitted to a remote TNode; determining (116) if the data packet to be transmitted is of a first data packet type or a second data packet type, different from the first data packet type; pre-coding (120) the data packet to be transmitted based on the obtained data packet type, wherein pre-coding (120) comprises: performing (122) pre-coding in a first pre-coding mode associated with a first beamwidth if the data packet to be transmitted is determined to be of the first data packet type; and performing (124) pre-coding in a second pre-coding mode associated with a second beamwidth if the data packet to be transmitted is determined to be of the second data packet type, wherein the second pre-coding mode is different from the first pre-coding mode, and wherein the first beamwidth comprises more spatial directions than the second beamwidth.

2. The method of claim 1, further comprising: obtaining (112) channel characteristics for a plurality of radio channels between the remote TNode and the multi-antenna transmitter and receiver arrangement (400); and wherein pre-coding (120) is further based on the obtained channel characteristics.

3. The method of claim 2, further comprising: deriving (114) a channel tap filter length from the obtained channel characteristics; and wherein performing pre-coding (120) in the first pre-coding mode comprises allocating (123) a first transmit power associated with a first number of channel taps; wherein performing pre-coding (120) in the second pre-coding mode comprises allocating

(125) a second transmit power associated with a second number, different from the first number, of channel taps; and wherein the first and second numbers of channel taps are less than or equal to the channel tap filter length.

4. The method of claim 3, further comprising: deriving (115) a time delay and a coefficient from the obtained channel characteristics; wherein performing (122) pre-coding (120) in the first pre-coding mode comprises utilizing

(126) a first set of phase shifts, scaling factors and time delays for the data packet to be transmitted, wherein performing (124) pre-coding (120) in the second pre-coding mode comprises utilizing (128) a second set of phase shifts, scaling factors and time delays for the data packet to be transmitted, and wherein the first and second sets of phase shifts, scaling factors and time delays are determined based on the channel tap filter length and/or the time delay and the coefficient derived from the obtained channel characteristics.

5. The method of any of claims 1-4, wherein the first data packet type is a retransmission of the data packet, and the second data packet type is a first transmission of a data packet.

6. The method of any of claims 1-4, wherein a data packet of the first data packet type comprises random access, common data information and/or control data, and a data packet of the second data packet type comprises dedicated data information.

7. The method of any of claims 1-6, further comprising: transmitting (130) the data packet to be transmitted.

8. The method of any of claims 1-7, wherein the first pre-coding mode has a first beamwidth; wherein the second pre-coding mode has a second beamwidth; and wherein the first beamwidth is broader than the second beamwidth.

9. The method of any of claims 1-8, wherein the pre-coding (120) is performed in one or more of a complex frequency domain, a wavelet domain, a frequency domain, a spatial domain and a time domain.

10. A computer program product comprising instructions, which, when executed on at least one processor of a processing device, cause the processing device to carry out the method according to any one of claims 1 to 9.

11. A non-transitory computer-readable storage medium storing one or more programs configured to be executed by one or more processors of a processing device, the one or more programs comprising instructions which, when executed by the processing device, causes the processing device to carry out the method according to any one of claims 1-9.

12. A multi-antenna transmitter and receiver arrangement (400), comprising control circuitry configured to cause: obtainment (310) of a data packet type for a data packet to be transmitted to a remote TNode; determination (316) of if the data packet to be transmitted is of a first data packet type or a second data packet type, different from the first data packet type; and pre-coding (320) of the data packet based on the obtained data packet type, wherein pre-coding (120) comprises: performing (122) pre-coding in a first pre-coding mode, associated with a first beamwidth, if the data packet to be transmitted is determined to be of the first data packet type; and performing (124) pre-coding in a second pre-coding mode, associated with a second beamwidth, wherein the second pre-coding mode is different from the first precoding mode, if the data packet to be transmitted is determined to be of the second data packet type, and wherein the first beamwidth comprises more spatial directions than the second beamwidth. 13. The multi-antenna transmitter and receiver arrangement of claim 12, wherein the control circuitry is further configured to cause: transmission (330) of the pre-coded data packet.

14. The multi-antenna transmitter and receiver arrangement (400) of any of claims 12-13, comprising: a transmitter arrangement (404) comprising: a pre-coder (1980) configured to pre-code data packets in a complex frequency domain, a wavelet domain, or a frequency domain; a first beamforming processing unit (1940) configured to convert the pre-coded data packets from a complex frequency domain, a wavelet domain, or a frequency domain to a time domain; a second beamforming processing unit (1810) configured to process the pre-coded data packets in one or more of a spatial domain and a time domain to obtain digital signals; a control unit (1920) configured to determine coefficients for the first and/or the second beamforming processing unit (1940, 1810); combiners (1840, ..., 1847) configured to combine the digital signals to obtain combined digital signals; conversion units (620, ..., 635) configured to convert each of the combined digital signals to respective analog signals; and transceivers (500, 501, ..., 515) configured to transmit each of the analog signals via antenna units (700, 701, ..., 715).

15. The multi-antenna transmitter and receiver arrangement (400) of claim 14, further comprising: a receiver arrangement (402) comprising: analog to digital converters (600, 601, ..., 615) configured to convert analog radio signals into digital radio signals; an extraction unit (900) configured to extract reference signals from each of the digital radio signals; and a channel analyzer (920) configured to determine characteristics for each of the digital radio signals based on the extracted reference signals; wherein the transceivers (500, 501, ..., 515) configured to transmit each of the analog signals via antenna units (700, 701, ..., 715) are further configured to receive analog radio signals via the antenna units (700, 701, ..., 715).

16. The multi-antenna transmitter and receiver arrangement (400) of claim 15, further comprising: a switch (406) configured to switch the transceivers (500, 501, ..., 515) between the transmitter arrangement (404) and the receiver arrangement (402). 17. A wireless device, WD, comprising the multi-antenna transmitter and receiver arrangement (400) of any of claims 12-16.

18. A transceiver node, TNode, comprising the multi-antenna transmitter and receiver arrangement (400) of any of claims 12-16.